Efficiency Optimization, Method 2; Determining The Optimum Flux From The Motor Thermal Model; Qualitative Result Of Efficiency Optimization, Method 2 - Siemens SINAMICS G120XA Operating Instructions Manual

Advanced commissioning
6.9 Energy saving
However, in all applications, speed and torque are specified by the driven machine. As a
consequence, the remaining variable for the efficiency optimization is the flux.
The converter has two different methods of optimizing the efficiency.

Efficiency optimization, method 2

Generally, energy efficiency optimization method 2 achieves a better efficiency than method 1.
We recommend that you set method 2.
Figure 6-80
Based on its thermal motor model, the converter continually determines - for the actual
operating point of the motor - the interdependency between efficiency and flux. The converter
then sets the flux to achieve the optimum efficiency.
Figure 6-81
Depending on the motor operating point, the converter either decreases or increases the flux
in partial load operation of the motor.
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Determining the optimum flux from the motor thermal model

Qualitative result of efficiency optimization, method 2

Operating Instructions, 03/2019, FW V1.0, A5E44751205B AB
SINAMICS G120XA converter